To test a region of interest in a patient, it may be necessary to biopsy a tissue sample. When the region of interest is a lung, transbronchial needle aspiration (“TBNA”) may be used to obtain a tissue sample from a lymph node. In TBNA, generally, a distal end of n bronchoscope is inserted through the patient's mouth and into the lung. A device, which may generally include a catheter, a general hollow needle disposed within the catheter, and a stylet disposed within the needle, can be inserted through a working channel of the bronchoscope and directed towards the lymph node. The stylet may be disposed within the needle such that the distal ends of the stylet and the needle are substantially aligned so that as the device is advanced towards the lymph node, the distal end of the stylet can block or prevent debris (i.e., tissue, blood, and the like) from entering the needle.
Once the device is near the lymph node, the stylet can be withdrawn from the needle so that a space for collecting tissue samples is created in the needle (i.e., a sample storage area). Once the stylet is withdrawn, an ancillary suction or vacuum device can be connected to a proximal end of the bronchoscope and/or the needle. The needle can then be advanced towards the lymph node so that a needle tip can penetrate, cut, core, and/or shear a tissue sample from the lymph node. The tissue sample can be aspirated into the sample storage area via the ancillary suction or vacuum device. Once a sufficient tissue sample is collected, the device can be removed from the bronchoscope. Once removed, negative suction can be applied to the device so that the sample tissue can be expelled from the needle and prepared for biopsy.
While the aforementioned devices and methods have proven satisfactory in the field, some difficulties exist. For example, in order to supply suction or vacuum to the sampling region, the stylet must be entirely withdrawn from the needle before the ancillary suction device can be attached. Because the stylet can be long, withdrawing the stylet from the needle can be cumbersome and may undesirably add time to the procedure. Moreover, subsequently attaching the suction device to the needle can also be cumbersome and add additional time to the procedure. Further, as the needle is advanced towards the lymph node, the needle may errantly penetrate blood vessels causing unnecessary bleeding. The application of suction may then aspirate blood into the sample storage area and deep into the needle, which may undesirably contaminate any collected tissue samples and/or make the collected tissue samples more difficult to process. In such a case, the device is typically removed from the bronchoscope and the patient, a fresh device is loaded into the bronchoscope and the patient, and another attempt is made to penetrate the lymph node. The application of suction may also aspirate tissue samples beyond the sample storage area and deep into the needle, which may make expelling the tissue sample difficult. This is especially true when the tissue samples are small and/or when the ancillary vacuum or suction device is difficult to control.
Accordingly, what is needed is a device that can create a local and controlled vacuum at a distal end of the device. What is needed is to provide a localized vacuum at a distal end of the device without attaching ancillary generators, equipment, and/or other external suction or vacuum devices. If would be desirable to provide a device that does not require entirely withdrawing the stylet from the needle in order to collect tissue samples. It would be desirable to provide a device that does not require entirely withdrawing the stylet from the needle in order to aspirate tissue samples into the sample storage area. It would be attractive to provide an improved tissue-sampling device suitable for use in transbronchial needle aspiration procedures. It would be attractive to prevent aspirating tissue samples past a sample storage area in a sampling needle. It would be desirable to provide a device that can be mass-produced relatively inexpensively, that has a minimal number of parts, and that is easy to operate. It would be desirable to provide a method for obtaining a tissue sample from a site or region of interest for biopsy.
While U.S. Patent Application Publication Numbers 2011/0144661 and 2014/0081318 appear to provide tissue-sampling devices, the teachings of which are entirely incorporated by reference herein for all purposes, these devices appear to have or include one or more of the aforementioned difficulties. Moreover, unfortunately, these devices do not appear to solve or provide any of the desired improvements previously described.